Automatic synchronizer.



PATENTED APR. 21, 1908.

, F. CONRAD.

AUTOMATIC SYNGHRONIZBR.

APPLICATION FILED FEB. 2, 1907.

2 SHEETS-SHBET 1.

- INVENTOR z g ATTEJRNEY W|TNESSES2 PATENTED APR. 21, 1908.

F. CONRAD.

AUTOMATIC SYNGHRONIZER.

APPLICATION FILED FEB. 2, 1907.

' 2 SHEBTS-SHEET 2.

, v 1 Y r 1 I INVENTOR $4M W WlTN ESSES 2 Maw UNITED STATES PATENT OFFICE.

FRANK CONRAD, OF SWISSVALE, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

AUTOMATIC SYN CHRON IZER.

Specification of Letters Patent.

Patented April 21, 1908.

Application filed February 2, 1907. iicrial No. 355,501

To all whom it may concern:

Be it known that I, FRANK CONRAD, a citizen of the United States, and a resident of Swissvale, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Automatic Synchronizers, of which the following is a specification.

My invention relates to means for automatically connecting an alternatingcurrent generator to a circuit when the currents generated thereby agree in phase and frequency with those in the circuit.

The object of my invention is to provide a structure and arrangement of parts, for.

means of the character indicated, that shall render the operation thereof more satisfactory and effective than others heretofore provided. 4 In Patent No. 819,787, granted May 8th, 1906, to Westinghouse Electric 8: Manufacturing Company, as assig'nee of Hugh J. McMahan, is set forth a device for so governing the operation of switches that are adapted to connect two ormore alternating current generators in parallel that closure of the coupling switches maybe effected at substantially the instant when the machines reach synchronism.

The device includes a switch for controlling the circuits of the closing magnet wind ings of the coupling switches that comprises amovable conducting segment and amovable and a stationary brush that are adapted to cooperate therewith, both brushes engaging the conducting segment only when the machines are approximately in synchronism.

1n the operation of the device, the movable brush is moved periodically into and out a view, in front elevation, of a device that embodies my invention, the cover for the device having been removed. Fig. 2 is a plan view of the device of Fig. 1, the casing being shownin section, and Fig. 3 is a diagrammatic yiew illustrating the circuit connec tions of the device of the preceding figures and the mode of o eration thereof.

The structure 0 the device to which the invention is here applied issubstantially like that which forms the subject-matter of the aforesaid Patent No. 819,787, the operating parts of which are mounted upon a back plate or base 2 and areinclosed and. protected by a cover 3 which may be suitably fastened to the base 2. Projecting forwardly from the base 2 are a plurality of posts 4, to

the outer ends of which is fastened a frame plate 5, by means of screws 6. The frame plate 5 is also provided with a plurality of posts 7, to the outer ends of which is fastened a plate 8, by means of screws 9. The parts thus far described constitute the frame which supports the movable parts of the instrument.

Journaled in suitable bearings, one of which is attached to the base 2 and the other to the frame plate 5, is a shaft 10, upon which is rigidl mounted an arm or bar 11 that projects t erefrom in "both directions.- The outer ends of the arm or bar 11 are respectively connected to'magnetizable cores 13 and 14 by means of coil springs 17 and 18 so that, as either core is drawn downward, the corresponding end 'of'the arm or bar 11 will be lowered to correspondingly rock the shaft 10 in its bearings. The niagnetizable core 13 is subjected to the influence of two sets of series-connected coils 15 and 16 that alternate in position and are so arranged as to act in conjunction upon the core 13 when the currents which traverse them are of the same phase. The core 14 is similarly subjected to the influence of two sets of series-connected coils 15 and 16 that alternate in position but are so arranged as to act in op osition When the currents which traverse t em are of the same phase, coils15 bein connected in series with the coils 15 and coi s 16 in series with. coils 16.

The end of the bar 11 that is connected to the solenoid core 14 is provided with an angular bracket arm'19, the free end of which is en agement Wit pivotally connected to'the up er end of a dashpot cylinder 20. The brac et arm 19 18 also provided with a contact brush 21 that proj ects inwardly substantially parallel to the base 2 toward the rock shaft 10. The end of the bar 11 that is connected to the solenoid core 13 is provided with a suitable wei ht 22 to counterbalance the dashpot cylinc er 20 and the other parts which are supported by the correspondm end ofthe bar 11.

The rod 23 of tie dashpot piston 24 is pivotally connected to one end of a bell-crank lever 25 that is supported on a short shaft or pivot 26 which has its bearings in the plates 5 'and 8. The end of the lever 25 to which the piston rod 23 is connected is also connected to a post 27 that projects from the base 2, by means of a coil-spring 28, a screw 29 being provided for adjusting the amount of pull exerted by the spring. The other end of the lever 25 is connected, by means of a link 30, to the outer end of an arm 31 which is loosely mounted upon a short shaft 32, the respective ends of which are journaled in the frame late 5 and the plate 8. The weights of the inks and levers are counterbalanced by means of a weight 32 that is adjustable in position upon a screw-threaded rod 32 which forms an extension of one arm of the bell-crank lever 25.

The portion of the arm 31 adjacent to the shaft 32 is provided with a pin 33 in the outer end of which a screw 33 is threaded. Rigidly mounted'upon the shaft 32, between the plates 5 and 8, is a segmental block 34,prefer ably formed of insulating material and provided with a in 35 that is adapted to engage the end 0 the screw 33". The pin 35 is connected to a hub 36 of the arm 31, by means of a spiral s ring 37 which tends to move the segmenta block 34 from left to right and, conse uently, to hold the pin 35 in the screw 33. The perip ery of the segmental block 34 is provided with a conducting plate or stri 3 the outer surface of which is substantia ly flush with. the peripheral surface of the block at one end, and at the other end of the block is cut away to provide an offset.

The brush contact member 21, to which reference has already been made, makes engagement at its free end with the peri hery ofthe segmental block 34 and a similar brush contact member 40 is pivotally mounted u on a pin 41 at the end of an arm 42 adjusta ly supported by means of a slot and screw connection 43 with the frame plate 5, so that it may be adjusted to vary the position of the free end of the brush 40 with reference to the contact stri or plate 38 with which the segmental bloc 34 is provided.

Securedto the lower side of the brush contact member ,40, and near its free end, is a block 44 that is adapted to engage a pin-or stop 45, which projects from the face of the segmental block 34, when the member 40 becomes disengaged from the conducting strip 38. A helical tension spring 46, the ends of which are secured, respectively, to the block 44 and to a post 47 upon the arm 42, causes the contact member 40 to exert suflicient' pressure upon the conducting strip 38 to insure goodfelectrical connection between those parts. Projecting from the upper side of the contact member 40, near its free end, is a hook or catch 48 with which a post 49, that is carried by the bar 11, is adapted to engage when the right-hand end of the bar is raised, the contact member 40 being thereby raised in order to cause the block to become disengaged from the stop 45 and to permit rengagement thereof with the conducting strip 38.

Referring now to Fig. 3, in connection with the preceding figures, two alternating current machines'50 and 51, which may be assumed as indicative of any number of generators, rotary converters or synchronous motors which it may be desired to connect in parallel to either supply or utilize alternating current energy, are respectively provided with double pole switches 52 and .53 by means of which the machines may be connected to bus bars 54 and 55. 1t will be understood that the bus bars 54 and 55 may be connected, by means of suitable conductors, to translating devices, in the usual manner, and that it is therefore unnecessary to illustrate such translating devices and circuit connections.

I have shown each of the switches 52 and 53 as provided with means for automatically closing .the same, such means being intended merely as indicative of any suitably operated devices for this purpose As here shown, the movable contact members of the switch 52 are connected together by a bar 56 and the corresponding members of the switch 53 are similarly connected together by a bar 57. Each pair of movable members is connected, by means of a cord or band 58, to a wei ht 59, the cord or band being provided wit 1 a catch or stop device 60 and being guided and supplorted by a suitable roller 61.

T e switches are normally held in open position by reason of the engagement with the catches 60 of projections 62 from cores 63 of solenoids 64, these projections being withdrawn to permit the weights 59 to close the switch when the solenoids are energized to raise their cores. The solenoids 64 are connected, in parallel, to a normally open circuit 65-66 that is supplied with energy from a suitable source, such as a battery 67.

v The brushes 21 and 40 of the controller constitute the terminals of the battery circuit and that circuit is therefore closed only when both brushes are in contact with the strip or plate 38 of the segmental block 34. This condition is attained when and only when the machines 50 and 5l attainsynchronous operation, and this condition may be brought about by the arrangement of connections constituting the present invention.

The coils and 15 are adapted to be connected to the one or the other of the generators 50 and 51 by means of double-throw switches 68 and 69, and the coils 16 and 16 are adapted to be connected to the bus bars 54 and 55 by means of a double-throw switch 70. Thus it is seen that one set of coils for each of the magnetizable cores 13 and 14 is adapted to be supplied from the circuit 5455, and that each of the other sets of coils .is adapted to be supplied from the generator which it is intended to connect to said circuit. It will also be understood that when the currents in the two sets. of coils are in phase with each other; that is, when the currents supplied by the generator are in phase with the currents in the'circuit 5455, the righthand end of the bar 11 will be drawn downward, and when the currents are not in phase the left-hand end of the bar will be drawn downward.

The remainder of the operation of the device is substantially like that of the aforesaid patent except that when the-currents agree in phase, but differ considerably in frequency, the core 13 will be quickly drawn downward and the segmental block 34 will be moved from right to left a greater distance than that through which. it ordinarily moves, thus permitting the free end of the brush 40 to become disengaged therefrom and also permitting the block 44 to engage the stop 45. The brush 40 is, in this manner, locked in position out of enga ement with the connecting strap 38 until t 1e pin 49 engages the hook 48 and releases the block 44 from engagement with the stop 45. This action cannot take place, however, until-the brush 21 becomes disengaged from the conducting strip 38. Thus the device prevents con nection of the generator to the bus bars when the currents differ materially in frequency even though they agree in phase.

I claim as my invention:

1. The combination .with a pivotally mounted switch member having a conducting and a non-conducting portion, a pivoted bar having a contact member that cooperates with the switch member, and means for operatively co'nnectingthe pivoted bar to the switch member, of another contact member that normally engages the conducting portion of the switch member but becomes disengaged therefrom upon movement of the switch member to an extreme position, means for thereafter maintaining the said contact member out of engagement with the conducting portion of the switch member, and means operated by the'vpivoted bar to cause them to rengage.

2. The combination with a pivotally mounted switch member having a conducting and a non-conducting portion, a pivoted bar having a contact member that cooperates with the switch member, and means for operativelyconnecting the pivoted bar to the switch'member, of another contact member that normally engages the conducting portion of the switch member but becomes disengaged therefrom upon movement of the switch'member to an extreme position, and means for preventing rengagement of the said parts until the pivoted bar occupies a predetermined position.

" 3. The combination with a pivotally mounted switch member having a conducting and a non-conducting portion, a pivoted bar having a contact member that oooperates with the switch member, and means for operatively connecting the pivoted bar to the switch'member, of another contact member that normally engages the conducting portion of the switch member but becomes disengaged therefrom upon movement ofthe switch member to an extreme position, and means for preventing rengagement of the said parts while the brush that is carried by the pivoted bar engages the conducting portion of the switch member. I

4. The combination with a pivotally mounted switch memberhaving a conduct ing and a nonconducting portion, a stop carried thereby, a pivoted bar having a contact member that cooperates with the switch member, and means for operatively connectcatch from the stop when the pivoted bar oc cupies a predetermined position.

5'. The combination witlrtwo sources of alternating current, and a part that reciprocates in response to the variations in the phase relations of the currents, of a switch comprising three cooperating members one of which is operated directly by the reciproeating part, another of which is operatively connected to the reciprocating part, and the third of which engages the second member except when the latter is moved to an extreme position, means for'maintaining the second and third members out of engagement, and means actuated by the reciprocating part for causing ren agement of said members only when pre etermined phase relations exist between the currents.

6. The combination with-two sources of alternating current, and a part that reciprocates in response to the variations in the phase relations of the currents, of a switch comprising three cooperating members one of which is operated directly by the reciprocating part, another of Which is operatively connected to the reciprocating part, and the third of which engages the second member except when the latter is moved to an extreme position, means for maintaining the second and third members out of engagement, and means for causing rengagement of said members only when the reciprooat 11g part is moved to a predetermined position.

In testimony whereof, I have hereunto subscribed my name this 26th day of January, 1907.

FRANK CONRAD. Witnesses:

O AALBORG, BIRNEY HINEs. 

